Ear defenders for fastening to a protective helmet, in particular for forestry workers

ABSTRACT

An ear protection to be fastened to a protective helmet, particularly for forestry workers, is described. The ear protection comprises two ear protectors each of which comprises a fork-like supporting bracket comprising ear protection capsule pivotably supported thereon and a rotary plate connected to the supporting bracket by a tilting joint in relation to which the supporting bracket can be bistably tilted into an extended and into a retracted position. The rotary plate is rotatably supported in a receiving part attached to the helmet. A yoke spring disposed between the rotary plate and the supporting bracket pre-stresses the supporting bracket to abut on stoppers defining the extended and the retracted position of the supporting bracket. The receiving part is attached to the inside of the helmet. The ear protectors are therefore rotatable into a parking position within the helmet.

The invention relates to an ear protection to be fastened to a protective helmet, particularly for forestry workers, comprising two ear protectors each of which comprises: a fork-like supporting bracket on which an ear protection capsule is pivotably supported, a rotary plate jointedly connected to the supporting bracket in relation to which the supporting bracket is bistably tiltable into an extended and into a retracted position, and a receiving part attachable or attached to a helmet in which the rotary plate is rotatably supported and which is pivotable between an operating position and a parking position defined by stoppers.

Such an ear protection is known from the DE 10 2007 011 110 A1 which will be referred to in more detail further below.

A protective helmet comprising such an ear protection is known from the document DE 8714490 U1. The protective helmet is comprised of a helmet shell and interior fittings. The interior fittings are comprised of a crossed strap by means of which the helmet is worn on the head and which ensures a shock absorbing distance between the head and the helmet shell. The helmet has, at its outer circumference, a protrusion encompassing the lateral and the rear part of the helmet which is provided with four recesses for fastening the crossed strap and other recesses for fastening additional attachment elements at the lower edge. The additional attachment elements may be added or removed as required. At the broadest positions of the helmet a recess is provided on the outside of the protrusion encompassing the largest part of the helmet. This is the attachment position of, among other items, the ear protection. The ear protection is comprised of two ear protectors respectively comprising a wire bracket and an ear protection capsule. The ear protection is, together with a face protection, fixed to the outside of the helmet by means of a common connecting piece which is inserted into the protrusion. Disadvantageous in a helmet equipped like such is that, in use, obstacles the helmet passes engage behind the brackets of the ear protection capsules and, in this way, impair the wearer of the helmet on duty or may tear the helmet from his or her head and thereby endanger the wearer.

An ear protection known from the DE 10 2007 011 110 A1 already mentioned in the beginning comprises a device for attaching an ear protection capsule to the outside of a protective helmet. Here, a protective helmet is referred to in which the helmet design is, by default, customized so that two ear protectors can be releasably attached to the outside of the helmet at its edge on each side of the helmet above the position of the ear in a slot or the like provided in the helmet there. For this purpose, a receiving part or each ear protector is formed so that it can be fixed in the slot by means of a snap-on fastening. The ear protectors are worn in an operating position during work in which the ear protection capsules are in a retracted position in which they tightly abut the ears. The ear protectors can be moved into a standby position from the operating position if the ear protection is temporarily unnecessary. In this position, the ear protection capsules are located in an extended position in which they are still positioned above the ears, however, pivoted away from the ears to the outside. The ear protection capsules may also be retained in this position, for example, to enable a conversation during work. Finally, a break or parking position exists for the ear protectors. In the parking position, the ear protection capsules are pivoted upwards from the operating position towards the rear side and on the outside of the helmet. For the ear protection capsules to be movable past the edge of the helmet into the parking position, it is required to first bring the ear protectors into the standby position. Retaining each ear protection capsule in the extended or retracted position is rendered possible by a double-tongued leaf spring jointedly connecting the supporting bracket of the ear protection capsule to a rotary plate of the ear protector and having two bistable positions.

One problem to be solved by the known ear protection is seen in retaining the supporting bracket including the ear protection capsule in the parking position since the ear protection capsule, due to gravity, strives to rotate downwards and back into the standby position from the parking position. To prevent such a downwards rotation, it was common that the user pivots the supporting bracket to the inside in its parking position in which it is tilted upwards so that the bistable leaf spring presses the ear protection capsule to the helmet shell from the outside. In this way, relatively large forces were generated on the helmet, for example, at the mount of the supporting bracket on the helmet, which gave rise to the risk that the helmet and/or the supporting bracket were damaged. The known ear protection is therefore formed so that a safe positioning of each ear protection capsule in an upturned parking position outside of the helmet is effected. To this end, the receiving part comprises a projection protruding substantially parallel to the axis of rotation which restricts a movement of the rotary plate in a specific rotational position when abutting to the supporting bracket in the known ear protection. In the known ear protection, the solution of the problem is complicated by the use of a bistable leaf spring which is, indeed, supposed to render it possible that the supporting bracket, together with the ear protection capsule, occupies a defined extended or retracted posture in the operating or standby position, but, at the same time serves to jointedly connect the supporting bracket to the rotary plate and can therefore not have an exactly defined tilting point and cannot ensure a defined exertion of pressure on the ear by the ear protection capsule in case of different head sizes of helmet users. Since the jointed connection between the supporting bracket and the rotary plate is only established by the bistable leaf spring and depends on its two bistable end positions, the supporting bracket neither has an exactly defined extended position nor an exactly defined retracted position which impedes an adjustment of the ear protection to different head sizes.

The fixation of the ear protector in the parking position is effected with the aid of a stopper supported by the leaf spring abutting on a projection of the receiving part. However, this support is dependent on the friction of the leaf spring on the projection and may therefore change in the course of time. The force in the direction towards the operating position required on the rotary plate to move the mentioned stopper out of engagement may therefore decrease in the course of time so that the user might, nevertheless, attempt to prevent an undesired downwards rotation of the supporting bracket with the aid of the ear protection capsule by pivoting the ear protectors inwards on the outside of the helmet in the parking position so that the ear protection capsule is pressed against the helmet shell from the outside.

It is the object of the invention to design an ear protection of the type mentioned in the beginning so that the abovementioned problems are eliminated, i.e., in particular that the risk that a helmet may get caught on obstacles in use due to the ear protection attached to it and that an ear protector may unintentionally rotate back into the protecting position from the parking position is removed.

According to the invention, this object is solved by the supporting bracket and the rotary plate being connected to each other by a tilting joint, a tilting axis of which penetrates the supporting bracket and the rotary plate, by a yoke spring disposed adjacent to the tilting joint between the rotary plate and a free end of the supporting bracket pre-stressing the supporting bracket to abut on additional stoppers defining the extended and the retracted position to thereby effect its bistable tiltability and by the receiving part being designed for an attachment on the inside of a helmet.

According to the invention, the receiving part is mounted on the inside of a helmet so that the ear protection capsules and the associated supporting brackets are located substantially within the perimeter of the protective helmet. The helmet therefore does not offer any possibilities for obstacles such as branches and the like to get caught on its outside. If the ear protection is not required, the ear protectors may be rotated backwards into the parking position which is located within the helmet within the perimeter of the protective helmet.

Due to the attachment of the receiving part of each ear protector on the inside of the helmet, particularly on the inside of the helmet shell, in addition to the supporting brackets and the ear protection capsules, the receiving parts are also protected against an external exertion of a force by obstacles the helmet may contact. Furthermore, the supporting brackets are pivotable between the standby position and the parking position within a clearance between helmet shell and interior fittings due to the receiving parts being mounted on the inside of the helmet, i.e., they are always located within the perimeter of the helmet shell. Accordingly, the supporting bracket and the ear protection capsules do not offer any catching or engagement points for obstacles in either position.

Due to the fact that in each ear protector of the ear protection according to the invention the supporting bracket and the rotary plate are connected to each other by a tilting joint a tilting axis of which penetrates the supporting bracket and the rotary plate, the drawbacks resulting from a bistable leaf spring being used for jointedly connecting the supporting bracket to the rotary plate are eliminated. In the ear protection according to the invention, the tilting axis constitutes a defined centre of rotation which does not change in the course of time. Furthermore, according to the invention, the yoke spring being located adjacent to the tilting joint between the rotary plate and a free end of the supporting bracket and pre-stressing the supporting bracket only ensures the build-up of a force between the supporting bracket and the rotary plate, i.e., it does not simultaneously define the extended and the retracted position of the supporting bracket. These positions are rather determined by defined stoppers. The yoke spring only provides the force for moving the supporting bracket towards these stoppers. The yoke spring together with the other stoppers therefore establishes defined end positions for the supporting bracket when it is extended and retracted and thus ensures its bistable tiltability between defined stoppers.

In the ear protection according to the invention, the yoke spring does not have the function of a joint supporting the supporting bracket but only serves to build up a force with the aid of which the supporting bracket can be retained in a defined extended and in a defined retracted position on the additional stoppers. The problem of an undesired downward rotation of the ear protector from the parking position downwards in the direction of the standby position is strongly reduced if not eliminated by the ear protection according to the invention because the ear protection capsule will be positioned on the inside of the helmet and on the outside of interior fittings of the helmet in the parking position and will therefore have a substantially reduced tendency to rotate downwards from the parking position as a result of pressure from both sides.

Advantageous embodiments of the ear protection according to the invention constitute the subject matter of the subclaims.

In one embodiment of the ear protection according to the invention, an eccentric bolt for adjusting the initial load applied to the supporting bracket by the yoke spring is rotatably arranged in the rotary plate and in contact with the yoke spring. It is therefore possible to adjust the magnitude of the force with which the ear protection capsule is pressed against the ear in the retracted position of the supporting bracket in a simple manner.

In a further embodiment of the ear protection according to the invention, a slide pre-stressed in the direction towards the rotary plate by a pressure spring is shiftably supported at the free end of the supporting bracket, said slide comprising a retaining lug which can be brought in contact with a slide path on the receiving part and being prevented from being shifted in its retracted position and not being prevented from being shifted in its extended position by the supporting bracket and releasably retaining the supporting bracket in its parking position by means of an engagement in a recess in the slide path of the receiving part. The spring pre-stressed slide is, in this embodiment of the invention, retained in engagement with the rotary disk in a position in which the free end of the supporting bracket engages in a recess of the slide. The recess of the slide thus forms one of the additional stoppers defining the retracted position of the supporting bracket. On the other hand, the free end of the supporting bracket abuts to the rotary disk in a recess which consequently constitutes one of the other stoppers and defines the extended position of the supporting bracket. In this latter position, the slide is shiftable on the supporting bracket along the slide path on the receiving part in the direction opposite to the rotary plate against the force of the pressure spring so that the supporting bracket including the rotary plate can be pivoted in the receiving part and the supporting bracket including the ear protection capsule can be located in the parking position.

In a further embodiment of the ear protection according to the invention, a groove extending at least over a semi-circle for accommodating a circular arc-shaped shoulder of the rotary plate is formed in the receiving part. The rotary plate is guided in the receiving part during its rotation.

In a further embodiment of the ear protection according to the invention, a resilient tongue protruding from the receiving part engages in a complementary depression in the rotary plate for locking the mutual engagement of the receiving part and the rotary plate, and a push button for releasing the fixation is arranged in the rotary plate. The supporting bracket may, in this way, be locked in place by a snap-on fastening together with its rotary plate in the receiving part and released by operating the push button.

Embodiments of the invention will be described in more detail below with reference to the drawings in which:

FIG. 1 shows a protective helmet comprising an ear protection according to the invention, a helmet shell being shown in a sectional view and two ear protectors constituting the ear protection being shown in a standby position, i.e., pivoted away from the ears,

FIG. 2 shows the protective helmet according to FIG. 1, the ear protectors, however, being shown in an operating position, i.e., retracted on the ears;

FIG. 3 shows a side view of the protective helmet according to FIG. 2;

FIG. 4 shows the protective helmet according to FIG. 3, the ear protection according to the invention, however, being pivoted into a parking position and accommodated within the helmet;

FIG. 5 shows the protective helmet according to FIG. 4 in a view from below, only one ear protector of the ear protection according to the invention on one side a being shown;

FIG. 6 shows a face view of one of the two ear protectors of the ear protection according to the invention;

FIG. 7 shows a front view of the ear protector according to FIG. 6;

FIG. 8 shows the ear protector according to FIGS. 6 and 7 in a side view and in the standby position;

FIG. 9 shows a rear view of the ear protector according to FIG. 6;

FIG. 10 shows a longitudinal sectional view of the upper part of the ear protector according to FIG. 8;

FIG. 11A shows the upper part of the ear protector according to FIG. 7 together with a receiving part and pivoted into the parking position;

FIG. 11B shows a side view of the ear protector according to FIG. 11A;

FIG. 12A shows the ear protector according to FIG. 11A pivoted back into the standby position;

FIG. 12B shows a side view of the ear protector according to FIG. 12A;

FIG. 13A shows the ear protector according to FIG. 12A, however, in the operating position;

FIG. 13B shows the ear protector according to FIG. 13A in a side view; and

FIG. 14 shows, as a detail, the helmet shell of the protective helmet according to FIG. 5 in a perspective representation and in an inclined view from below, the interior fittings not being shown and a receiving part of only one ear protector which is attached to the inside of the helmet shell being shown for the sake of clearness.

A protective helmet designated by 30 in its entirety and comprising an ear protection 33 according to the invention which is designed, particularly for use in forestry, is shown in different views in FIGS. 1 to 5 and 14. The ear protection 33 comprises two ear protectors 34 a, 34 b. The protective helmet 30 comprises a helmet shell 36 and interior fitting subassembly designated by 40 as a whole and comprising a supporting cage 42, a head band 44, and a neck band 46. The neck band 46 is provided with a tightening unit designated by 48 as a whole.

Three supporting arms formed as spacers of which only the supporting arms 54 and 55 can be seen in FIGS. 1 and 2 serve as means for a three-point attachment of the interior fittings or the interior fitting subassembly 40 to the helmet shell 36. The helmet shell 36 is dimensioned so (i.e., its interior width is dimensioned so long and so broad) and the supporting arms are dimensioned and arranged so that a clearance 60 for accommodating ear protection capsules 35 a, 35 b of the ear protectors 34 a or 34 b and other helmet accessories as well as mounting devices for the ear protection 33 is present between the interior fitting subassembly 40 and the helmet shell 36. The other helmet accessories include the abovementioned tightening unit 48 of the neck band 46. In relation to the ear protection 33, the clearance 60 is determined so that the ear protection capsules 35 a, 35 b abut to the inside of the helmet shell 36 and to the outside of the interior fitting subassembly 40 in the parking position as can be seen in FIG. 5.

A mounting device for the ear protection 33 comprises two receiving parts 80 a, 80 b attached to the inside of the helmet shell 36. The receiving parts 80 a, 80 b are pivot bearings for supporting brackets 37 a, 37 b together with the ear protection capsules 35 a or 35 b as described in more detail further below. The receiving parts 80 a, 80 b are respectively integrally formed on the inside of the helmet shell 36 as a bearing cup of the pivot bearings or, preferably, fixedly mounted as additional parts.

The ear protection 33 will now be described in more detail with reference to the drawings, particularly to FIGS. 1-5 and 14. FIG. 14 shows the helmet shell 36 without the interior fitting subassembly 40 in an inclined view from below, particularly the position of the receiving part 80 a on the inside of the helmet shell 36 being illustrated. The other receiving part 80 b which cannot be seen is inversely attached to the opposite side. FIG. 1 shows the protective helmet 30 with the ear protection 33 provided on both sides, the helmet shell 36 being shown in a sectional view, and the ear protectors 34 a, 34 bbeing shown in the extended state, i.e., pivoted away from the ears in the standby position. FIG. 2 shows the protective helmet according to FIG. 1, the ear protectors 34 a, 34 b, however, being shown in the retracted state on the ears in the operating position. FIG. 3 shows a side view of the protective helmet according to FIG. 2. FIG. 4 shows the protective helmet according to FIG. 3, the ear protectors 34 a, 34 b, however, being shown when pivoted rearwards into a parking position and accommodated in the helmet 30.

The two ear protectors 34 a, 34 b comprise the two ear protection capsules 35 a, 35 b which are pivotably supported in the fork-like supporting bracket 37 a or 37 b, respectively. The inside of the helmet shell 36 is provided with the fixedly attached receiving parts 80 a, 80 b. In the receiving parts 80 a, 80 b, the supporting brackets 37 a, 37 b are rotatably supported with rotary plates 39 a or 39 b jointedly attached to their free ends as can be seen in FIGS. 6 to 13. The receiving parts 80 a, 80 b and the supporting brackets 37 a, 37 b are arranged and formed so that the supporting brackets 37 a, 37 b are pivotable between two positions within the clearance 60, namely, the operating position shown in FIGS. 2 and 3 in which the ear protection capsules 35 a, 35 b are pivoted away from the ears and the parking position shown in FIG. 4 in which the ear protection capsules 35 a, 35 b are accommodated in the clearance 60 in the helmet 30.

Each supporting bracket 37 a, 37 b is designed so as to be spring pre-stressed and bendable in an area between its two ends in which it extends within the clearance 60 so that the ear protection capsules 35 a, 35 b are pivoted away from the ear in the non-bent position of each supporting bracket 37 a, 37 b, respectively, as shown in FIG. 1, and pivoted onto the ear in the bent position of the supporting bracket 37 a, 37 b, respectively, as shown in FIG. 2. If the protective helmet 30 is not placed on the head, the two ear protection capsules 35 a, 35 b respectively reach a position which is located substantially further inward than the ear on which each ear protection capsule 35 a, 35 b is to abut. In other words, the distance between the ear protection capsules is, in this case, substantially smaller than the distance between the ears. In this way, it is ensured that the ear protection capsules 35 a, 35 b are kept pressed to the ears by the spring pre-load when the helmet 30 is put on. The spring pre-load for bending each supporting bracket 37 a, 37 b between two defined positions (bistable) is exerted by a circularly bended yoke spring 92 a, 92 b (as can be seen, for example, in FIG. 7). Each supporting bracket 37 a, 37 b can be manually moved into the retracted and into the extended position. In each of these positions, the yoke spring 92 a or 92 b effects an end position lock in cooperation with a stopper described further below, respectively. The end position lock of the supporting bracket 37 a, 37 b should not be reached if the helmet is put on and each ear protection capsule 35 a, 35 b is to be kept resiliently pressed to the ear.

In addition, each receiving part 80 a, 80 b and each supporting bracket 37 a, 37 b including the rotary plate 39 a, 39 b are formed so that the supporting bracket can only be pivoted backwards from the position shown in FIG. 1. In this way, it is ensured that the ear protection capsules 35 a, 35 b can be accommodated within the clearance 60 behind the ear without colliding with the ears and the lower edge of the helmet shell 36. FIG. 6 shows a rear view of the ear protectors 34 a,b of the ear protection 33. The ear protectors 34 a and 34 b are identically formed, i.e., mountable on the right and on the left side of the helmet 30. The only thing different is the design of the receiving part 80 a, b since it has an increasingly descending slide path 86 a,b in a rearward direction. The receiving part 80 a is shown in FIG. 14. The receiving part 80 a is also shown in FIGS. 11-13.

According to the representation in FIG. 7 the ear protection capsule 35 a, b is pivotably supported on the fork-like supporting bracket 37 a,b. A rotary plate 39 a, b is jointedly connected to the supporting bracket 37 a,b by means of a tilting joint 82 a,b which can be seen in FIG. 8. The tilting joint 82 a,b is formed as a tilting axis 84 a,b formed as a rod-like axis inserted in holes in the supporting bracket 37 a,b and the rotary plate 39 a,b, thus penetrates the supporting bracket and the rotary plate. Owing to the existing tilting joint 82 a,b the supporting bracket 37 a,b can be tilted into the extended position (standby position) and into the retracted position (operating position) if the ear protector 34 a, b is located in its position on the ear. In the operating position shown in FIG. 13, the ear protection capsule 35 a,b abuts on the ear. Alternatively, the ear protector 34 a,b may occupy the standby position in which it is extended, i.e., in which the ear protection capsule is not pressed against the ear. This standby position is shown in FIG. 12. In the operating position according to FIG. 13, the ear protector 34 a,b is only pivotable in a reduced angular range. In the standby position according to FIG. 12, the ear protector 34 a,b is pivotable into the parking position shown in FIG. 11. The receiving part 80 a,b which is usually fixedly attached to the inside of the helmet 30, to be more precise, on the inside of the helmet shell 36, is also shown in FIGS. 10-13 for explanatory reasons. The rotary plate 39 a,b is rotatably supported in the receiving part 80 a,b and pivotable between the standby position according to FIG. 12 and the parking position according to FIG. 11. The operating position and the parking position are defined by stoppers which will be described in more detail below.

In the standby position of the ear protector 34 a,b shown in FIG. 12, the free end 38 a, b of the supporting bracket 37 a,b which is pivoted away from the ear is retained on a stopper 41 a,b by the pre-stressing force of the yoke spring 92 a,b formed by a cover plate 51 a,b rigidly connected to the rotary plate 39 a,b. The initial load of the yoke spring 92 a,b keeps the supporting bracket 37 a, b stably abutting on the stopper 41 a, b. Opposite to the stopper 41 a,b, the receiving part 80 a, b has a recess 89 a, b in which the free end 38 a,b of the supporting bracket 37 a,b is pivotable from the standby position shown in FIG. 12B into the operating position shown in FIG. 13B. A wall of the receiving part 80 a,b facing the stopper 41 a,b forms another stopper 43 a,b on which the free end 38 a,b of the supporting bracket 37 a,b is held by the initial load of the yoke spring 92 a,b in the operating position shown in FIG. 13B. The supporting bracket 37 a,b hinged to the rotary plate 39 a,b blocks a rotation of the supporting bracket 37 a,b into the parking position shown in FIG. 11 with its free end 38 a, b in the operating position.

The pivotability and non-pivotability of the rotary plate 39 a,b are determined by a slide 98 a,b shown in a sectional view in FIGS. 10-13. The slide 98 a,b is shiftably supported on an extension of the rotary plate 39 a,b above the free end 38 a,b of the supporting bracket 37 a,b and pre-stressed by a pressure spring 98 a,b in the direction towards the rotary plate 39 a, b. The receiving part 80 a, b is provided with a slide path 86 a,b at its lower edge. In FIGS. 10-13, only the receiving part 80 a mounted on the left inner face of the helmet is shown. Accordingly, the slide path is only designated by 86 a in these Figures. The slide 98 a,b comprises a retaining lug 104 a,b which can be brought in contact with the slide path 86 a,b at the receiving part 80 a,b and is prevented from being shifted by the supporting bracket 37 a,b in its retracted position according to FIG. 13B but is not prevented from being shifted in its extended position according to FIGS. 11 and 12. The slide 98 a,b is not prevented from being shifted by the supporting bracket 37 a,b placed in the extended position and releasably retains the supporting bracket 37 a,b in its parking position by the engagement in a recess 87 a, b in the slide path 86 a,b of the receiving part 80 a,b. The slide 98 a,b is shifted by the rotational movement from the standby position according to FIG. 12 into the parking position according to FIG. 11. The shifted slide 98 a,b does no longer permit the supporting bracket 37 a,b to be pivoted in the direction of the operating position, i.e., in the direction of the retracted position of the supporting bracket 37 a,b. In the standby position according to FIG. 12, the slide 98 a, b is free, and the supporting bracket 37 a,b is therefore pivotable into the parking position according to FIG. 11. In the operating position according to FIG. 13, the slide 98 a, b is not shiftable so that the supporting bracket 37 a,b including the ear protection capsule 35 a,b is not pivotable into the parking position. This pivotability is only given again if the supporting bracket 37 a,b is pivoted back into the standby position according to FIG. 12 in which the free end 38 a,b of the supporting bracket 37 a,b does not abut on the stopper 88 a, b from the operating position according to FIG. 13.

In the receiving part 80 a,b, a groove 85 a,b is formed which extends over at least a semi-circle and serves to accommodate a circular arc-shaped shoulder 49 a,b of the rotary plate 39 a,b as can be seen in FIG. 10. In FIG. 10, it can be further seen that the receiving part 80 a,b comprises a resilient tongue 81 a,b protruding towards the rotary plate 39 a,b. The resilient tongue 81 a, b engages in a complementary depression 83 a,b in the rotary plate 39 a, b to lock the mutual engagement of the receiving part 80 a,b and the rotary plate 39 a,b. In the rotary plate 39 a,b, a push button 50 a b for releasing the restraint is provided. When operating the push button 50 a,b in FIG. 9, the resilient tongue 81 a,b in FIG. 10 is pushed to the right whereby the snap-on fastening between the receiving part 80 a, b and the rotary plate 39 a,b is released again.

Each ear protection capsule 35 a,b is concavely curved in the longitudinal direction on its side facing the ear so that it can more readily adjust to the shape of the ear and the head. This results in an improved pressure distribution on the ear and enables a better closure against the entry of noise in combination with a reduced application of pressure.

LIST OF NUMERALS

-   30 protective helmet -   33 ear protection -   34 a,b ear protector -   35 a,b ear protection capsule -   36 helmet shell -   37 a,b supporting bracket -   38 a,b free end -   39 a,b rotary plate -   40 interior fitting subassembly -   41 a,b stopper (standby position, supporting bracket) -   42 supporting cage -   43 a,b additional stopper (operating position, supporting bracket) -   44 head band -   46 neck band -   48 tightening unit -   49 a,b circular arc-shaped shoulder -   50 a,b push button -   51 a,b cover plate -   54 supporting arm -   55 supporting arm -   60 clearance -   80 a,b receiving part -   81 a,b resilient tongue -   82 a,b tilting joint -   83 a,b complementary depression -   84 a,b tilting axis -   85 a,b groove -   86 a,b slide path -   87 a,b recess -   88 a,b retaining lug -   89 a,b recess -   92 a,b yoke spring -   94 a b eccentric bolt -   96 a,b pressure spring -   98 a,b slide 

1. An ear protection to be fastened to a protective helmet comprising two ear protectors each of which comprises: a fork-like supporting bracket on which an ear protection capsule is pivotably supported, a rotary plate jointedly connected to the supporting bracket in relation to which the supporting bracket can be bistably tilted into an extended and into a retreated position, and a receiving part attachable or attached a to a helmet in which the rotary plate is rotatably supported and pivotable between a protecting position and a parking position defined by stoppers, wherein the supporting bracket and the rotary plate are connected to each other by a tilting joint a tilting axis of which penetrates the supporting bracket and the rotary plate, in that a yoke spring disposed adjacent to the tilting joint between the rotary plate and a free end of the supporting bracket pre-stresses the supporting bracket to abut on further stoppers defining the extended and the retracted position and ensures its bistable tiltability in this way, and in that the receiving part is designed to be attached to the inside of a helmet.
 2. The ear protection according to claim 1, wherein an eccentric bolt rotatably disposed in the rotary plate and in contact with the yoke spring for adjusting the initial load applied to the supporting bracket by the yoke spring.
 3. The ear protection according to claim 1, wherein at the free end of the supporting bracket, a slide pre-stressed in the direction towards the rotary plate by a pressure spring is shiftably supported on an extension of the rotary plate which comprises a retaining lug which can be brought in contact with a slide path on the receiving part and is prevented from shifting by the supporting bracket in its retracted position and not prevented from shifting by the supporting bracket in its extended position and releasably retains the supporting bracket in its parking position by means of an engagement in a recess in the slide path of the receiving part.
 4. The ear protection according to claim 1, wherein by a groove which is formed in the receiving part and extends over at least a semi-circle for receiving a circular arc-shaped shoulder of the rotary plate.
 5. The ear protection according to claim 4, wherein a resilient tongue protruding from the receiving part for engaging in a complementary depression in the rotary plate for locking the mutual engagement of the receiving part and the rotary plate and for releasing the retainment by means of a push button disposed in the rotary plate. 